1. Field of the Invention
This invention relates to a pivot-and-positioning assembly, more particularly to a pivot-and-positioning assembly for a portable electronic device, such as a portable computer.
2. Description of the Related Art
FIGS. 1 and 2 illustrate a conventional pivot-and-positioning assembly 13 which connects a display module 11 and a main board module 12 for a portable computer 1. The pivot-and-positioning assembly 13 includes a mounting seat 131 secured to a rear end of the main board module 12, and a rotatable member 132 pivoted to a rear end of the display module 11 and mounted rotatably on the mounting seat 131 so as to permit rotation of the display module 11 relative to the main board module 12 about a first axis (X) and about a second axis (Z) between first and second positions. The mounting seat 131 includes a cylindrical member 139 with a cylindrical inner face 133 that is formed with a pair of diametrically disposed retaining grooves 134. The rotating member 132 includes a tubular element 135 that is rotatably received in the cylindrical member 139 and that is formed with a pair of diametrically disposed engaging grooves 136 which are aligned with and which confront the retaining grooves 134, respectively, when the display module 11 is positioned at the first or second position. A pair of elastic engaging plates 137 are respectively mounted in the retaining grooves 134, and are respectively formed with engaging tongues 138 that engage releasably and respectively the engaging grooves 136 so as to position the display module 11 at the respective one of the first and second positions.
The conventional pivot-and-positioning assembly is disadvantageous in that since the retaining grooves 134 and the engaging grooves 136 are formed in cylindrical faces, a relatively high precision is required for the formation of the same so as to permit radial alignment of the retaining grooves 134 with the engaging grooves 136 upon rotation of the display module 11 to the first and second positions. As such, a small deviation from the aforesaid radial alignment (see FIG. 3) or a larger clearance between the engaging ones of the engaging tongue 138 and the respective engaging groove 136 for accommodating the whole engaging tongue 138 in the engaging groove 136 can't make the position fixed. As a consequence, the conventional pivot-and-positioning assembly further includes an auxiliary positioning member 2 (see FIG. 4) to enhance positioning of the display module 11.